This invention relates to nuclear reactor cooling systems in general and more particularly to an improved cooling system which, through sharing of various elements, substantially reduces the overall cost of the cooling system.
In a typical nuclear reactor a plurality of various cooling circuits are generally provided. First there is the primary circuit in which coolant flows between the reactor and the steam generators. In this circuit, water is supplied to the reactor where it is heated and the steam generated therefrom in the steam generators, is used to drive power generating equipment, after which the water is pumped back to the reactor. A second type of cooling circuit is that used for cooling fuel elements which have been removed from the reactor core. Even after removal from the core, these fuel elements continue to give off heat and radiation. Thus they are generally placed in a cooling well where they are submerged in a coolant which is continually recirculated to remove the heat generated by the fuel elements.
A third type of cooling system found in reactors is the after cooling system or shutdown cooling system which is used to cool the core after shutdown. Since, at this time, the primary circuit is no longer in operation the residual heat in the reactor must be removed by a separate shutdown cooling system which circulates coolant through the reactor until it is completely cooled. As a safety measure there is also required in reactors an emergency cooling system which will supply coolant to the reactor should one of the primary coolant lines break. Associated with this there may also be a sprinkler system which is used to condense the steam from the primary circuit or that generated when the coolant escaping from a break comes in contact with the hot areas of the reactor and turns to steam.
In each of these systems or circuits there are of course a great number of elements such as piping, control valves, check valves, pumps, etc. Thus if portions of these systems can be effectively combined a substantial reduction of system elements and thus a reduction in overall system cost will result.